Light beam generator and have the optical projection system of this light beam generator
Technical field
The present invention relates to a kind of optical technology, particularly relate to a kind of light beam generator and have the optical projection system of this light beam generator.
Background technology
In recent years, fast development along with information industry and opto-electronics, make the application diversification more of data, and the application of optical projection system also is used in various occasions more widely, for example in the meeting in required projection bulletin, the meeting-place required image projecting or or even family in play the required image projecting of film and drama etc.And in the middle of the design of optical projection system, the intensity of light source is one of most important factor normally, and generally, the brightness of the strong more then projection of light source is high more, and relative drop shadow effect is also good more.
As shown in Figure 1, it shows the synoptic diagram of existing optical projection system, and optical projection system 1 is made up of light supply apparatus 11, colour wheel (color wheel) 13, light pipe (light pipe) 15 and imaging device 17.Light supply apparatus 11 is used to produce light beam, and is projected in the light pipe 15 after colour wheel 13 filters.Colour wheel 13 is the axle center with rotating shaft 131, be arranged on rotationally between light supply apparatus 11 and the light pipe (or claiming the light tunnel) 15, be used in order with different polaroids (polarize) light beam that polarizes, and then export red, blue, green three kinds of monochromatic light, carry out color modulation for imaging device 17, light pipe 15 then be used for the monochromatic light homogenising that will receive and raise the efficiency after be projected to imaging device 17.The light beam of 17 pairs of light pipes of imaging device 15 output is handled, and image frame is modulated in the light beam and forms image strip, and then image strip carried out projection and images on the projection screen 19.
The light supply apparatus 11 of above-mentioned optical projection system 1 is made up of bulb 111 and lampshade 113, and wherein bulb 111 is used to produce light, and lampshade 113 then is used for the light that bulb 111 is produced is pooled light beam, to provide optical projection system 1 required light.Under this design, if want to promote the image brilliance of 1 projection of optical projection system, then must increase the luminous power of bulb 111, yet, the way that increases bulb 111 luminous powers will directly cause the lifting of working temperature, and the lifting of bulb 111 working temperatures not only can influence the life of product of the light valve (light valve) in the imaging device 17, also derives simultaneously to cause bulb 111 to burn mistake, thereby reduces the work efficiency and the life of product of optical projection system 1.In addition, the design of setting up heat abstractor is proposed in No. 594372 patent of invention though announce at TaiWan, China,, this design has increased the volume of light supply apparatus undoubtedly, also cause optical projection system bulky, be difficult to microminiaturized shortcoming.
In order to improve the drop shadow effect of above-mentioned optical projection system 1, and the intensity of light source awkward situation that is difficult to promote, TaiWan, China is announced in No. 587195 patent of invention and is proposed a kind of light supply apparatus that is installed in the projector, is used to produce converging beam, light supply apparatus includes a plurality of light beam generators that are used to produce light beam, and the light beam that is used to make a plurality of light beam generator to produce produces deflection, the light beam that a plurality of light beam generator was produced is pooled the prism of converging beam.Because this specially uses a plurality of light beam generators and a prism in the preceding case of example, and each light beam generator also comprises bulb and collimating apparatus (collimator), cause bulkiness, the optical projection system of light supply apparatus bulky undoubtedly, be difficult to microminiaturized shortcoming, be difficult to microminiaturization so the projector of using light source device is equally too huge.
For being difficult to microminiaturization and the intensity of light source, the volume that improves above-mentioned existing optical projection system is difficult to the problem that effectively promotes, progressively developing employing light emitting diode (LED) cooperates collimating apparatus to produce light beam, and the design that the display element (as LCD (LCD), liquid crystal on silicon (LCOS)) that cooperates liquid crystal type produces image is as disclosed correlation techniques of case such as U.S. Patent Publication No. 2003/0133080, No. 2005/0219475 and No. 2005/0190307.Because light emitting diode has the advantage of high color representation and low electric weight demand, can make the comparatively miniaturization of optical projection system that is constituted.
Because the display element of liquid crystal type can only be accepted the light source of particular polarization direction, and light emitting diode is not to all the winds luminous as bulb, but has the hemisphere face emitting characteristics, therefore, in order to promote the output usefulness and the efficient of light beam generator, more seem especially important for design and relative position that the collimating apparatus that collimates effect is provided.
As shown in Figure 2, disclosed light beam generator 2 comprises light emitting diode 21 and has the optical element 23 of reflecting surface 231 in No. 2005/0190307 case of U.S. Patent Publication, and in fact the optical element 23 with reflecting surface 231 is exactly a collimating apparatus.The reflecting surface 231 of optical element 23 is curved design, and light emitting diode 21 is disposed in the light path by reflecting surface 231 reflection of optical element 23 and output beam.That is to say, the light source of launching from light emitting diode 21 is after the reflecting surface reflection coupling of optical element 23, will be staggered with light emitting diode 21 once more, therefore, partly the light after the coupling will be covered by light emitting diode 21, cause the loss of optical efficiency significantly, moreover the volume of light-emitting component 23 is also excessive.
In the preceding disclosed light beam generator 2 of case of above-mentioned United States Patent (USP), cause except the optical efficiency of tangible loss output beam the not good shortcoming of output usefulness, because light emitting diode 21 itself has circuit and heat dissipation design, after the coupling of this light source once again with the staggered design of light emitting diode 21, also obviously increase the weight of the burden of the required heat dissipation design of light emitting diode 21, be unfavorable for the lightening of applied optical projection system.In addition, because the not good cause of light beam generator 2 output usefulness, for the liquid crystal type display element that can only accept particular polarization direction light source, to be difficult to the intensity of light source that provides enough, therefore cause the luminance shortage of projection image, so can't be used in the optical projection system of light source polarization conversion demand.
Therefore, how effectively to solve disclosed existing in prior technology problem, become the problem that needs to be resolved hurrily at present.
Summary of the invention
The shortcoming of prior art in view of the above the purpose of this invention is to provide and a kind ofly promotes the light beam generator of light beam output efficiency and have the optical projection system of light beam generator.
Another object of the present invention provides a kind of light beam generator and has the optical projection system of light beam generator, in the optical projection system that is provided for light source polarization conversion demand.The light beam output efficiency can be promoted, radiating requirements can be reduced.
Another purpose of the present invention provides and a kind ofly reduces the light beam generator of radiating requirements and have the optical projection system of light beam generator.
For reaching above-mentioned purpose and other purpose, the invention provides a kind of light beam generator, it comprises: optical element have aspheric reflecting curved surface, and reflecting curved surface has a focus at least; And light emitting diode, the focus that it is disposed at optical element is used to emit beam to reflecting curved surface, to be directed to specific direction.
Light emitting diode can be selected from one of them of ruddiness, blue light, green glow and white light emitting diode.In a preferred embodiment, light emitting diode is naked wafer form, and in a further advantageous embodiment, light emitting diode is a packing forms.
The present invention also provides a kind of optical projection system, it comprises: light beam generator, it comprises optical element and light emitting diode, optical element has aspheric reflecting curved surface, and reflecting curved surface has a focus at least, and light emitting diode is disposed at the focus of optical element, is used to emit beam to reflecting curved surface, is directed to the light beam of specific direction with formation; The collimated illumination device is used to receive the light beam from light beam generator, and gives homogenising and raise the efficiency; And imaging device, be used to receive light beam, and image frame is modulated in the light beam and forms image strip, for to outer projection from the collimated illumination device.
In the above-mentioned optical projection system, can comprise the light beam generator that a plurality of symmetric array are arranged, the collimated illumination device can be selected from one of them of array lens and light tunnel, imaging device can comprise display element and projection lens, and wherein, display element can be selected from LCD, liquid crystal on silicon and digital micro-mirror device (Digital Micromirror device, DMD) one of them.In addition, the light emitting diode of each light beam generator can be selected from the wherein permutation and combination of the two at least of ruddiness, blue light, green glow and white light emitting diode.
In the light beam generator and optical projection system that the invention described above provided, reflecting curved surface can be a high reflectance parabolic shape curved surface, also can be high reflectance elliptical area type curved surface; In addition, reflecting curved surface can be made of the metal coating of optical element surface, also can be made of the dielectric plated film of optical element surface.In addition, reflecting curved surface can satisfy following curvilinear equation formula:
Wherein, k is the constant of the cone, and c is a curvature, α
1To α
7Be asphericity coefficient.
Light beam generator proposed by the invention and have the optical projection system of light beam generator, mainly used the relative configuration relation of the light emitting diode in the light beam generator with optical element, and the reflecting curved surface of optical element design, be used to prevent staggered once more after optical element reflection coupling of light that light emitting diode produces thus, therefore the light after the coupling does not have the situation of being covered by light emitting diode, so the optical efficiency that can avoid losing output beam, can promote the optical efficiency of institute's output beam relatively, and can reduce radiating requirements, so not only can dwindle the volume of light beam generator, also can make the relatively more slimming of applied optical projection system; Simultaneously, because light beam generator provided by the present invention does not have the light efficiency losses phenomenon of shading, can also effectively bring into play its best light extraction efficiency, so help controlling the light beam of output particular polarization direction, and then can be applicable in the optical projection system of light source polarization conversion demand, to cooperate the demand of liquid crystal type display element (for example LCD, liquid crystal on silicon, digital micro-mirror device).
Description of drawings
Fig. 1 shows the synoptic diagram of existing optical projection system;
Fig. 2 shows the synoptic diagram of the light beam generator in No. 2005/0190307 case of U.S. Patent Publication;
Fig. 3 A shows the synoptic diagram of light beam generator of the present invention;
Fig. 3 B shows the synoptic diagram that light state of light beam generator of the present invention;
Fig. 4 shows optical projection system synoptic diagram of the present invention; And
Fig. 5 shows the synoptic diagram of a plurality of light beam generator arrangement architectures in the optical projection system of the present invention.
The main element symbol description:
1 optical projection system, 11 light supply apparatuses
111 bulbs, 113 lampshades
131 rotating shafts of 13 colour wheels
15 light pipes, 17 imaging devices
19 projection screens, 2 light beam generators
21 light emitting diodes, 23 optical elements
231 reflectings surface, 3 light beam generators
31 light emitting diodes, 33 optical elements
331 reflecting curved surfaces, 4 optical projection systems
41 collimated illumination devices, 43 imaging devices
431 display elements, 433 projection lens
Embodiment
Below by specific instantiation explanation embodiments of the present invention, those skilled in the art can understand other advantage of the present invention and effect easily by the disclosed content of this instructions.The present invention also can be implemented or be used by other different instantiation, and the every details in this instructions also can be based on different viewpoints and application, carries out various modifications and change under the spirit of the present invention not deviating from.
Be noted that appended accompanying drawing is the synoptic diagram of simplification, basic structure of the present invention only is described in a schematic way.Therefore, in these accompanying drawings, only indicate the element relevant with the present invention, and shown element is not to be that number, shape, dimension scale etc. when implementing with reality drawn, specification during its actual enforcement is actual to be a kind of optionally design, and its component placement form may be more complicated, gives earlier and illustrate.
With reference to figure 3A and Fig. 3 B, the synoptic diagram that it shows the synoptic diagram of light beam generator of the present invention respectively and goes out light state, light beam generator 3 as shown in the figure comprises light emitting diode 31 and optical element 33.Light emitting diode 31 can be one of them of ruddiness, blue light, green glow and white light emitting diode for example, and in this preferred embodiment, light emitting diode 31 is packing forms, yet in other embodiments, light emitting diode 31 also can be naked wafer form.Optical element 33 can be made by for example material of high transmission rate such as plastics or glass.
Optical element 33 has aspheric reflecting curved surface 331, and reflecting curved surface 331 has a focus at least.In the present embodiment, reflecting curved surface 331 is high reflectance elliptical area type curved surfaces, but also can be high reflectance parabolic shape curved surface in other embodiments, and it satisfies following curvilinear equation formula:
Wherein, k is the constant of the cone, and c is a curvature, α
1To α
7Be asphericity coefficient, when k is-1, be high reflectance parabolic shape curved surface.
Reflecting curved surface 331 is formed on the inner surface of optical element, in the present embodiment, reflecting curved surface is electroplated by optical element 33 inner surfaces or the metal coating of evaporation constitutes, and certainly in other embodiments, also can be electroplated or the plated film of the multilayer dielectric material of evaporation constitutes by the optical element inner surface.
Light emitting diode 31 is disposed at the focus of the reflecting curved surface 331 of optical element 33, is used to emit beam to reflecting curved surface 331, to be directed to specific direction.Because light emitting diode 31 is disposed at the design of focus of the reflecting curved surface 331 of corresponding optical element 33, at first can prevent light the interlocking once more after the reflecting curved surface 331 reflection couplings of optical element 33 that light emitting diode 31 is produced, therefore the light after the coupling does not have the situation of being covered by light emitting diode 31, so can avoid losing the optical efficiency of output beam, can promote the optical efficiency of institute's output beam relatively.
Secondly, be disposed at the design of focus of the reflecting curved surface 331 of corresponding optical element 33 by light emitting diode 31, the light that light emitting diode 31 is produced is after the reflecting curved surface 331 reflection couplings of optical element 33, can be shown in Fig. 4 A the half-angle of bright dipping be controlled at very little angle, the curvature value of this angle value visual reflex curved surface 331 is with the size of light emitting diode 31 and slightly different, light emitting diode 31 for general 1mm * 1mm size, can be with full width at half maximum (Full width in halfmaximum, FWHM) be controlled at less than 8 degree, so can obviously promote the collimation effect of light beam generator and the optical efficiency of corresponding output beam.
In addition, because light beam generator 3 provided by the present invention is the light efficiency losses phenomenon of shading not, and by the particular arrangement relation of light emitting diode 31 with optical element 33, can also effectively bring into play its best light extraction efficiency, so help controlling the light beam of output particular polarization direction, thereby can be applicable in the optical projection system of light source polarization conversion demand, to cooperate the demand of liquid crystal type display element (for example LCD, liquid crystal on silicon, digital micro-mirror device).
Simultaneously, because light beam generator 3 provided by the present invention is the shading phenomenon not, therefore light beam can not repeat staggered to light emitting diode 31, so need not use special heat dissipation design, can reduce radiating requirements relatively, so not only can dwindle the volume of light beam generator 3, also can make the relatively more slimming of applied optical projection system.
With reference to figure 4 and Fig. 5, the present invention also provides a kind of optical projection system 4 with above-mentioned light beam generator, and as shown in the figure, optical projection system 4 comprises light beam generator 3, collimated illumination device 41 and the imaging device 43 that a plurality of symmetric array are arranged.Be noted that, though be in the present embodiment to comprise that the light beam generator 3 that a plurality of symmetric array are arranged is an example, usually know that the knowledgeable should understand but have in the art, also single beam generator 3 can only be set in other embodiments, and not with present embodiment quantity is set and Rankine-Hugoniot relations is restriction.
Light beam generator 3 is same as the previously described embodiments, comprise optical element 33 and light emitting diode 31, optical element 33 has aspheric reflecting curved surface 331 equally, and reflecting curved surface 331 has a focus at least, and light emitting diode 31 is disposed at the focus of optical element 33, be used to emit beam to reflecting curved surface 331, be directed to the light beam of specific direction with formation.In the present embodiment, consider the half-plane emitting characteristics of light emitting diode 31, a plurality of light beam generators 3 are arranged with symmetrical array, the effect that maximum light emitting diode 31 is set can be reached thus in minimum area, the slimming or the microminiaturized degree of optical projection system 4 can also be further promoted.In addition, in the present embodiment, reflecting curved surface 331 is to be example with high reflectance parabolic shape curved surface, and the light emitting diode 31 of each light beam generator 3 can be selected from the wherein any permutation and combination of the two at least of ruddiness, blue light, green glow and white light emitting diode.
Collimated illumination device 41 is used to receive the light beam from light beam generator 3, and gives homogenising and raise the efficiency, and in the present embodiment, the collimated illumination device is the array lens, also can be the light tunnel certainly in other embodiments.
Imaging device 43 is used to receive the light beam from collimated illumination device 41, and image frame is modulated in the light beam and forms image strip, for to outer projection.In the present embodiment.Imaging device 43 comprises it for example being display element 431 and the projection lens 433 of LCD, and display element 431 also can be liquid crystal on silicon or digital micro-mirror device in other embodiments certainly.Because imaging device 43 and above-mentioned collimated illumination device 41 are not creation emphasis of the present invention, and be the parts that the persond having ordinary knowledge in the technical field of the present invention can understand and can simply replace, its effect all is as good as with prior art with configuration, so no longer repeat to give unnecessary details at this.
Compared with prior art, light beam generator proposed by the invention and have the optical projection system of light beam generator, mainly used the relative configuration relation of the light emitting diode in the light beam generator with optical element, and the reflecting curved surface of optical element design, the light that prevents light emitting diode thus and produced staggered once more after optical element reflection coupling, therefore the light after the coupling does not have the situation of being covered by light emitting diode, so can avoid losing the optical efficiency of output beam, can promote the optical efficiency of institute's output beam relatively, and can reduce radiating requirements, so not only can dwindle the volume of light beam generator, also can make the relatively more slimming of applied optical projection system; Simultaneously, because light beam generator provided by the present invention does not have the light efficiency losses phenomenon of shading, can also effectively bring into play its best light extraction efficiency, so help controlling the light beam of output particular polarization direction, and then can be applicable in the optical projection system of light source polarization conversion demand, to cooperate the demand of liquid crystal type display element (for example LCD, LCOS, DMD).So light beam generator provided by the present invention and have the optical projection system of light beam generator has solved the existing in prior technology problem relatively.
The foregoing description has only exemplarily illustrated principle of the present invention and effect thereof, rather than is used to limit the present invention.Any technician of this area can be under the situation of spirit of the present invention and category, and the foregoing description is made amendment and changed.Therefore, claim protection domain of the present invention should be as claim be listed.